Abstract: ［Abstract］Objective　To investigate the different proteins between wild type N2 and hypoxia-sensitivity strain（ia04） and lay the foundation for studying the response mechanism of C.elegans during hypoxia．Methods　 The worms of two strains were cultured synchronously to L4 stage．Then the total proteins were extracted by using routine method. After that， two-dimensional electrophoresis was performed and the selected protein spots were then identified by MALDI/TOF/TOF tandem mass spectrometry and search the Swiss-Prot database. Go term （Gene Ontology） analysis was also performed．Results　Twenty-five significantly different spots were finally identified by MS（ratio＞2.0，P＜0.05）．The expression levels of main proteins identified in N2 were higher than those in ie04 strain: heat shock proteins （HSP-70 and HEP-60）， Putative GTP-binding protein（TAG-210），Probable medium-chain specific acyl-CoA dehydrogenase（GN＝T）．The expression levels of main proteins identified in ie04 strain were higher than those in N2 strain: Elongation factor-1 alpha（EFT-3）and Iron-sulfur protein（ISP-1）．The expression level of HSP in ie04 strain was obviously lower than in N2 strain，it may be the one reason why worms of ie04 strain were sensitivity to hypoxia. According to the Go term， most proteins identified were related to the development and DNA synthesis of C. elegans．Conclusions　Proteomic research can offer the valuable reference data to study the hypoxia in C. elegans．Different proteins found in different strains may promote the understanding of the hypoxia responsive mechanism and uncover the mechanism of important phenotype gene expression at the protein level.